1. Field of the Invention
The present invention relates to a mobile image apparatus such as a liquid-crystal television and a portable video apparatus, and more particularly, to a mobile image apparatus having an antenna disposed at least one of within said case unit and outside said case unit. The present invention also relates to an antenna apparatus associated with the above described mobile image apparatus.
2. Related Art of the Invention
FIG. 28 illustrates a conventional mobile image apparatus. A mobile image apparatus 450 has a case unit 451, an antenna 452 connected to the case unit 451, and an image display unit 453 for displaying radio waves carried on the antenna 452 as a video image.
Generally, the antenna 452 is an elastic monopole antenna, and is formed by, as shown in FIG. 29, mounting a radiation device 455 having a length of 1/4 .lambda. (.lambda.: the wavelength at a resonant frequency) on a ground, for example, a case unit. One end of the radiation device 455 serves as a power supply section 456 connected to a power supply source V, while the other end of the radiation device 455 serves as an open end 457. When the antenna 452 is pulled out for use, the radiation device 455 is extended to be about 1/4 .lambda..
However, the above known type of mobile image apparatus presents the following problem. The length of the radiation device while the receiving operation is performed is .lambda./4, the radiation device is extended to be approximately 60 cm Accordingly, the mobile image apparatus is unstable and falls or bends even with a small impact. Thus, the mobile image apparatus is dangerous and difficult to use.